JPS59204628A - Preparation of rigid foam - Google Patents

Abstract

PURPOSE:In preparing rigid foam by blending a polyol containing a specific polyol, a specified blowing agent, etc. with an isocyanate component, to improve compatibility of the polyol with the blowing agent, by adding a specific surface active agent to the polyol component. CONSTITUTION:A polyol component containing a polyol having >=100, preferably 150-800 average hydroxyl number [preferably polyester polyol or polyol consisting of poly(ester)ether polyol containing oxyethylene group as main component], a halogenated hydrocarbon blowing agent (preferably trichlorofluoromethane) in >=an amount solubilizable in the polyol, a polyoxyethylene aliphatic ester surface active agent (preferably polyoxyethylene-castor oil surface active agent having >=50 number of oxyethylene groups) and a catalyst (e.g., isocyanate trimerization catalyst) is blended with an isocyanate component containing a polyisocyanate compound, expanded and cured.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing rigid foams such as polyurethane-modified polyin cyanurate foams and rigid polyurethane foams, and particularly relates to methods for producing rigid foams such as polyurethane-modified polyin cyanurate foams and rigid polyurethane foams. The present invention relates to a method for manufacturing a rigid foam.

When producing rigid 7 ohm foams such as polyurethane-modified polyin cyanurate foams and rigid polyurethane foams, polyol components prepared by adding blowing agents, catalysts, etc. to polyols in advance are often used. This polyol component is sometimes called a polyol system liquid, and the method for producing foam using this polyol component and isocyanate component is sometimes called a premix method. One problem with this blowing agent-containing polyol component is the blowing agent--the compatibility of the rhodanized hydrocarbon blowing agent and the polyol. Since the norodanized hydrocarbon foaming agent is hydrophobic, when used in combination with a relatively hydrophilic polyol, the two are likely to separate and it is difficult to form a uniform component. Even if a tank containing a polyol component is used while stirring, it is difficult to take out a polyol component with a uniform ratio if there is a large difference in the properties of the two.

Hydrophobic polyols tend to include polyether polyols, which contain relatively many oxypropylene groups as oxyalkylene groups; hydrophilic polyols include polyether polyols, polyether polyols, and polyether polyols, which contain relatively many oxyethylene groups. Examples include low molecular weight polyols such as polyhydric alcohols. Therefore, it is considered that a highly hydrophobic polyol should be used to solve the problem of compatibility. However, the type of polyol has many effects on the type and physical properties of the rigid foam. Therefore, there are many fields in which hydrophilic polyols must be used. for example,
If a highly reactive polyol is required, a polyether polyol with a high primary hydroxyl value, ie a relatively high bone polyether polyol containing oxyethylene groups, is used. Further, when producing a urethane-modified polyisocyanurate foam, it is preferable to use a polyether polyol or polyester polyol with a high content of oxyethylene groups in order to improve its heat resistance and flame retardancy. Therefore, the method of using hydrophobic polyols with high compatibility cannot be applied to fields where these highly hydrophilic polyols must be used. Second, there is a problem related to the amount of blowing agent used. Even if the polyol is hydrophobic, if the amount of halogenated hydrocarbon blowing agent used increases, the amount dissolved in the polyol will be limited. Thus, for example, in the production of low density rigid polyurethane foams using large amounts of blowing agent, compatibility problems may arise even when using hydrophobic polyols. Furthermore, urethane-modified polyisocyanine v-)
When producing foam, the amount of polyol used is smaller than in the case of rigid polyurethane foam because an excess of polyincyanate compound is used, and the amount of blowing agent used relative to polyol is significantly larger. Regardless of the properties of the polyol, the problem of A-eye melting is very serious.

As a means to solve the compatibility of the above-mentioned rhodanized hydrocarbon blowing agent and polyol in the production of rigid foam,
A method is known in which a halogenated hydrocarbon blowing agent is added to an isocyanate component. However, this method significantly increases the difference in the mixing ratio between the polyol component and the incyanate component, making it difficult to quantitatively and uniformly mix the two. In addition, a method is also known in which a hydrophilic polyol and a hydrophobic polyol are used together to improve the compatibility (for example, Japanese Patent Publication No. 57-2
However, as mentioned above, there is a risk of deteriorating the physical properties of the hard foam, and the degree of compatibility improvement is limited.
It is hard to say that there is a sufficient solution.

The present inventor investigated various additives in order to increase the compatibility of a halogenated hydrocarbon blowing agent with a polyol.

The use of a surfactant as an additive for solubilizing or dispersing a hydrophobic compound in a hydrophilic compound is considered to be an effective means.

Therefore, when various surfactants were investigated for their solubilizing effects or stably dispersing effects on polyols of halogenated hydrocarbon blowing agents, it was found that many surfactants had no effect or only had insufficient effects. There wasn't.

However, upon further investigation, it was discovered that a polyoxydiethylene fatty acid ester surfactant had a remarkable effect. The present invention relates to a method for producing a hard foam using this specific surfactant to improve compatibilization.That is, polyols or polyol mixtures having an average hydroxyl value of 100 or more, catalysts, etc. and a polyol component containing a non-rodanized hydrocarbon blowing agent and an isocyanate component containing a polyisocyanate compound, and in a method for producing a rigid foam by foaming and curing the mixture, the polyol component is 1. A method for producing a rigid foam, characterized in that the foam contains at least a soluble amount of a rhodanized hydrocarbon blowing agent and a polyoxyethylene fatty acid ester surfactant.

Polyoxyethylene fatty acid ester surfactants are nonionic surfactants that are obtained by adding ethylene oxide and other epoxides such as propylene oxide to alkylene oxides such as ethylene oxide, which have functional groups such as hydroxyl groups. agent is appropriate. When another epoxide is used in combination with ethylene oxide, it is preferable that the other epoxide is an alkylene oxide having 3 or more carbon atoms, and in the case where they are used together, the proportion of ethylene oxide in the total epoxide is about 80 molar or more. , particularly preferably 98 mol or more. Furthermore, when adding ethylene oxide and other epoxides, they can be added randomly (i.e., by mixing both), they can be added separately to form a block-like chain, or they can be added separately to form a block-like chain. It is also possible to combine both methods. Most preferred is a compound having substantially only oxyethylene groups as oxyalkylene groups. Examples of fatty acid esters include mono- or polyfatty acid esters of hydroxyl group-containing compounds such as glycerin and sorbitan. Epoxides such as ethylene oxide are added to functional groups of fatty acid esters, such as unesterified hydroxyl groups of hydroxyl group-containing compounds and unesterified hydroxyl groups and carboxylic acid groups of fatty acids. Suitable fatty acids are higher fatty acids having 8 or more carbon atoms and having or not having unsaturated or saturated hydroxyl groups. Particularly preferred are higher fatty acids having 10 to 20 carbon atoms, such as lauric acid, palmitic acid, stearic acid, ophinic acid, linoleic acid, rillic acid, and ricinoleic acid. In the case of a fatty acid having a hydroxyl group such as ricinoleic acid, all the hydroxyl groups of the hydroxyl group-containing compound such as glycerin triester may be esterified. However, in the case of fatty acids that do not have hydroxyl groups or other functional groups, at least one hydroxyl group in the hydroxyl group-containing compound must remain. In any case, the fatty acid ester needs to be a compound that has at least one functional group to which ethylene oxide can be added. must be a di) fatty acid ester. Preferred fatty acid esters are compounds having at least two hydroxyl groups. This is thought to be because the ethylene oxy, subadduct, etc. of this fatty acid ester have at least two hydroxyl groups and can react with the polyisocyanate compound and become part of the polyurethane chain.

The most preferred fatty acid ester is castor oil or hydrogenated castor oil. Castor oil is a glycerol triester of ricinoleic acid, and since ricinoleic acid has a hydroxyl group, castor oil is a fatty acid ester having three hydroxyl groups.

Hydrogenated castor oil is a saturated fatty acid triester obtained by hydrogenating the unsaturated double bonds of ricinoleic acid.
Similarly, it has three hydroxyl groups. Although castor oil contains other fatty acid glycerin esters than ricinoleic acid, the main component of the fatty acids (usually 80% by weight or more) is ricinoleic acid. Polyoxyethylene-added castor oil has a compound represented by the following formula [D] as a main component.

x + y −) −Z is usually an integer of 20 or more, especially 50 to
150 is appropriate. Polyoxyethylene-added hydrogenated castor oil is a compound obtained by changing the unsaturated group of the compound of the above formula ('I) to a saturated group.Furthermore, it is a compound of the following formula [11] which is obtained by adding ethylene oxide to glycerin and then esterifying it with ricinoleic acid. Compounds represented by are also preferred.

0-(OH20 Horse 0) XT1... [1] In the above formula [R], 1 + m 10 n is an integer greater than or equal to 1), l + 'm + n + x -1-y 10 Z is usually 20 or more An integer of from 50 to 150 is suitable. Similar to hydrogenated castor oil, hydrogenated compounds of the above formula (n) can also be used. In these compounds,
Part of the oxyethylene group (preferably 10 molar proportion or less)
may be substituted with other epoxide residues such as oxyalkylene groups, but preferably contains substantially only oxyethylene groups. These, formula [11 or formula [I[
] The compound represented by the formula, its hydrogenated product, or a compound in which a portion of its oxyethylene group is substituted with another oxyalkylene group is hereinafter referred to as a polyoxyethylene-castor oil surfactant.

The polyoxyethylene fatty acid ester surfactant used in the present invention is not limited to the compounds described above, but includes many oxyethylene groups such as polyethylene glycol mono- or di-fatty acid esters and at least one fatty acid residue. It may also be an ester having a group. However, preferably a nonionic surfactant obtained by adding substantially only ethylene oxide to the above-mentioned fatty acid ester-based hydroxyl group-containing compound is suitable, and more preferably a polyoxyethylene fatty acid having at least two hydroxyl groups. Ester-based surfactants are suitable. The most preferred compound is the polyoxyethylene-castor oil surfactant.

In the present invention, the amount of the polyoxyethylene fatty acid ester surfactant (hereinafter simply referred to as surfactant) used is determined by the relative amounts of the polyol and the halogenated hydrocarbon blowing agent, and the larger the amount of the blowing agent, the more active the surface is. It is necessary to increase the amount of agent. However, it is usually preferred to use at least 0.5 parts by weight, especially from 5 to 20 parts by weight, per 100 parts by weight of polyol. By using a surfactant, the amount of blowing agent greater than the amount that can be dissolved in ciboriol becomes soluble in the polyol. The more the amount of surfactant used, the more the amount of blowing agent solubilized in polyol increases. However, if the amount of surfactant used is excessive, the effect on the hard foam cannot be ignored. Therefore, if the amount of blowing agent is larger, it is possible that some blowing agent may remain that is not solubilized.

However, even with this non-solubilized blowing agent, the blowing agent can be uniformly dispersed in the polyol through the use of surfactants, resulting in a relatively stable dispersion. Problems caused by homogeneous mixtures are solved. The use of a surfactant in the present invention also has the effect of making it unnecessary to use an organosilicon foam stabilizer that is often used in the production of rigid foams.

Of course, it is possible to use an organosilicon foam stabilizer in the present invention.

The polyols in the present invention are polyols or polyol mixtures and have an average hydroxyl value of 100 or more. As long as the average hydroxyl value is 100 or more, the polyol mixture may contain one or more polyols having a hydroxyl value of less than 100. A more preferable average hydroxyl value of the polyols is about 150 to 800, and in this case too, polyols having a hydroxyl value outside this range may be included, and in some cases, polyols with a hydroxyl value lower than this range may be included. A combination of polyols having a hydroxyl value higher than this range may also be used. In the present invention, polyol refers to a compound having at least two alcoholic hydroxyl groups, and also includes compounds having other functional groups (eg, dialkanolamine). As a polyol,
Examples include polyether polyols, polyester polyols, polyester ether polyols, polyhydric flucols, and alkanolamines containing two or more hydroxyl groups. Since polyols with an average hydroxyl value of 100 or more are made of polyols with relatively low molecular weight, generally... Compatibility with rhodanized hydrocarbon blowing agents; Polyols containing a large amount of polyols have low compatibility with the rhodanized hydrocarbon blowing agent, and the present invention is therefore effective for this purpose.

Examples of polyols include the following compound polyether polyols: water, polyhydric alcohols, polyhydric phenols,
A compound obtained by adding ethylene oxide and/or propylene oxide to an initiator having at least two functional groups to which alkanolamines, polyamines, or other epoxides can be added.

Polyester polyol: A compound obtained by reacting a polyhydric alcohol with a polyhydric carboxylic acid or an acid derivative such as its anhydride.

Polyester ether polyol: A compound obtained by reacting an alkylene oxide with a polyhydric carboxylic acid or its acid derivative after or simultaneously with the reaction of a polyhydric carboxylic acid or its acid derivative, or a polyether polyol and a polyhydric carboxylic acid. Or, a compound obtained by reacting its acid derivative.

Polyhydric alcohols: ethylene glycol, x-y-lene gelicol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, glycerin, trimetherol pronocon.

Alkanolamines: jetanolamine, triethanolamine, diisopronoquinolamine.

As will be discussed below, the present invention is particularly suited to the production of urethane-modified polyisocyanurate foams. Hydrophilic polyols are particularly suitable as polyols for urethane-modified polyisocyanurate foams. In particular, polyether polyols, polyester ether polyols, or polyester polyols having many oxyethylene groups as oxyalkylene groups are suitable.

Suitable polyether polyols include polyether polyols in which at least 30 mole percent or more, especially 50 mole percent or more, of all oxyalkylene groups are oxyethylene groups, and furthermore, the oxyalkylene groups include substantially only oxyethylene groups. Polyether polyols having the following are preferred. Similarly, as the polyester ether polyol, a compound in which at least 30 moles or more, particularly 50 moles or more of all the oxyalkylene groups contained therein is an oxyethylene group is preferable. In addition, the polyester polyol preferably has at least one aromatic nucleus, and particularly polyether polyols that are polyhydric phenol (e.g., bisphenol A)-alkylene oxide adducts and aromatic polycarboxylic acids (or acid derivatives thereof). A polyester ether polyol obtained by using at least one, preferably both of these, and more preferably a polyester ether polyol having an aromatic nucleus in which the oxyethylene group in the oxyalkylene group contained is within the above range. The most preferred polyester ether polyol is a polyhydric phenol-alkylene oxide adduct and/or
or by using at least one of aromatic carboxylic acids (or its acid derivatives) and adding an alkylene oxide simultaneously with the polyester formation reaction or after the polyester formation, and in which oxyethylene groups in all the oxyalkylene groups contained are It is a polyester ether polyol within the above range.

As the polyester polyol, the above-mentioned Japanese Patent Publication No. 57-2
Known polyester polyols such as those described in Japanese Patent No. 2052 are suitable.

As the polyol for the urethane-modified polyisocyanurate foam, it is preferable to use the above-mentioned polyols, or a mixture of these polyols containing at least one of them as the main component, or a mixture of these polyols containing at least one of them as the main component. Mixtures with other polyols are also preferred. Particularly preferred is at least one of the polyester ether polyols mentioned above, or a polyol containing the polyester ether polyol as a main component in combination with a polyether polyol having a high content of oxyethylene groups. The polyhydric phenols include, for example, bisphenol A, bisphenol S5, bis(hydroxyphenyl)methane, and the phenol-formaldehylic acid includes, for example, phthalic acid, inphthalic acid, terephthalic acid, and their 10-genides. Other ρ carboxylic acids include, for example, cono-phosphoric acid, oxalic acid, adipic acid, het's acid, maleic acid, and het's acid containing 710 gen.

In the present invention, it is essential to use a rhodanized hydrocarbon blowing agent as a blowing agent, but water may also be used in combination. Examples of the rhodanized hydrocarbon foaming agent include trichlorofluoromethane, dichlorodifluoromethane, dichloromonofluoromethane, dibromomonofluoromethane,
Dichlorotetrafluoroethane, 1,1.2trichloro-1,2,2-trifluoroethane, methinone chloride, etc. can be used, and two or more of these can be used in combination.

A particularly preferred rhodanized hydrocarbon blowing agent is trichlorofluoromethane. The amount used is polyol 10
It is appropriate to use at least 20 parts by weight or more based on 0 parts by weight, but it is not limited to this if the solubility in the polyol is low. Preferably it is 40 to 200 parts by weight, especially 60 to 150 parts by weight. The amount of water used is not particularly limited, but is usually about 5 parts by weight or less per 100 parts by weight of polyol.

The polyol component in the present invention further includes a catalyst. Catalysts vary depending on the type of rigid foam; for example, when producing rigid polyurethane foam, suitable catalysts include tertiary amine catalysts such as triethylenediamine and/or organometallic compound catalysts such as diptyltin dilaurate. When producing a urethane-modified polyisocyanurate foam, an isocyanate hexamerization catalyst, such as an alkali gold scrap salt or other metal salt of an organic carboxylic acid,
Quaternary ammonium salts and phosphines are used, and in some cases, catalysts for producing polyurethane such as the above-mentioned tertiary amine catalysts may be used in combination. In addition, in the case of producing other rigid foams such as urethane-modified carbodiimide foams, appropriate catalysts may be used. Optional additives that can be added to the polyol component include, for example, foam stabilizers such as organic silicon foam stabilizers, stabilizers for preventing decomposition of halogenated hydrocarbon foaming agents, and low or high monohydric foam stabilizers. These include brittleness modifiers such as alcohol, plasticizers, hard foam stabilizers such as antioxidants and ultraviolet absorbers, pigments and colorants, fillers such as glass fiber, mica, and calcium carbonate, and flame retardants.

The incyanate component usually consists of only a polyisocyanate compound, but in some cases, additives that are non-reactive with the polyisocyanate compound, such as a portion of a halogenated hydrocarbon blowing agent or a filler, may be added. As the polyisocyanate compound, aromatic, aliphatic, alicyclic, and other polyisocyanate compounds and modified products thereof can be used, and aromatic polyisocyanate compounds are particularly suitable.

Two or more types of polyisocyanate compounds may be used in combination,
It may also contain impurities such as crude products. Examples of polyisocyanate compounds include tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenylisocyanate, naphthylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, inphorone diisocyanate, and modified products thereof include, for example, prepolymers. There are type modified products and carbodiimide modified products.

The amount of polyisocyanate compound used varies depending on the type of rigid foam intended. Number of total hydroxyl groups of a compound having hydroxyl groups such as polyol (add this number if it has other isocyanate-reactive groups such as amino groups)
When producing rigid polyurethane foam, α8 to 1.5, especially 0
．． A value of 9 to 1.3 is suitable, and in the case of producing urethane-modified polyisocyanurate foams, an excess amount of 1.5 to 20, especially 2.0 to 15 is suitable.

The method for manufacturing the hard foam according to the present invention is not particularly limited, and can be applied to, for example, a one-shot method or a method.

EXAMPLES The present invention will be specifically explained below using Examples and Comparative Examples, but the present invention is not limited to these Examples.

The following polyols were used in the examples and comparative examples.
The surfactant is as shown in H below.

Polyol Polyol A: 60 parts (by weight, the same applies hereinafter) of a compound obtained by adding 3 moles of propylene oxide to 1 mole of bisphenol A, 20 parts of phthalic anhydride, 20 parts of ethylene oxide, and 1 part of KOHα at 120°C. Hydroxyl value 20 obtained by removing unreacted substances under reduced pressure after reacting for a period of time.
0 polyester ether polyol.

Polyol B: 25 parts of 1,4-butanediol, 40 parts of phthalic anhydride, 55 parts of ethylene oxide, and K
A polyester ether polyol having a hydroxyl value of 300 obtained by reacting 0.1 part of OH in the same manner as above.

Polyol C: A polyester polyol with a hydroxyl value of 320 obtained by reacting a mixture of phthalate and adipic acid (weight ratio 4:1) with ethylene glycol.

Polyol D: polyethylene glycol with a hydroxyl value of 280.

Polyol E: A polyether polyol with a hydroxyl value of 300 obtained by adding ethylene oxide to sorbitol.

Polypropylene IP: A polyether polyol with a hydroxyl value of 300 obtained by adding propylene oxide to sorbitol.

■ Surfactant Surfactant a: Polyoxyethene-hydrogenated castor oil (oxyethylene group number 80) Surfactant b = polyoxyethylene-hydrogenated castor oil (oxyethylene group number -
100) Surfactant C: Polyoxyethylene-water hydrogenated castor extract oxyethylene group'1200) Surfactant d
: Polyoxyethylene-castor oil (oxyethylene group number: 100) Surfactant e: Polyoxyethylene-castor oil (1+ m+n == 10,
X+7+Z: l 00 ) Surfactant f: Polyoxyethylene-castor oil (oxyethylene group number: 10) Surfactant g: Nonylphenolethelene oxyto adduct (oxyethylene group number: 13) Surfactant h: Nonylphenolethelene Oxide adduct (oxyethylene group number 85) Reference example, comparative reference example polyol, R-11 (trichlorofluoromethane),
and a surfactant at a weight ratio of 100:X:10), and the uniformity of the liquid was observed after standing for 10 days. A foaming system in which 95% or more of the liquid was uniform was judged to be suitable for practical use. The results are shown in Table 1 (Reference Examples) and Table 2 (Comparative Reference Examples) below. In the table, ○ indicates that the liquid is uniform with a coefficient of 95 or higher, and × indicates that there is no uniform phase with a coefficient of 95 or higher.

Examples and Comparative Examples The polyol component of the following formulation was 47.0 (45 in the comparative example).
．． 0 parts) and 80 parts of "PAP Knee 135" (polymethylene polyphenylinocyanate manufactured by Kasei Upjohn Co., Ltd.) were mixed at a liquid temperature of 20°C, and 200 tym.
A urethane-modified polyisocyanurate foam was produced by foaming and curing in a hazy wooden box. Examples 1 to 6 After mixing the polyol components, the mixture was allowed to stand for 24 hours and then mixed with the incyanate component to produce foam. In Comparative Examples 1 to 6, foams were produced by immediately mixing the polyol component and then mixing it with the isocyanate component. Foams using the same polyol had almost the same physical properties in both Examples and Comparative Examples. Comparative Example 6 is an example in which the blowing agent was used in an amount soluble in the polyol.

Also, one day after the foam was manufactured, the flammability of the foam was determined to be A.
Tested according to STM I)-1692. These results are shown in Table 3 (Examples) and Table 4 (Comparative Examples) below.

Polyol component: polyol 2o parts incyanate trimerization catalyst (1) t'o.

Foam stabilizer (2) 1. o.

R-1123// Surfactant 2. o Note (1)
Quaternary ammonium salt catalyst (product name: “Dapco TMR”) (2) Silicone foam stabilizer manufactured by Tone Silicon Co., Ltd. (product name: “Dapco TMR”)
BB-195'') Table 3

Claims (1)

[Scope of Claims] 1. A polyol or a polyol mixture containing a polyol having an average hydroxyl value of 100 or more, a halogenated hydrocarbon blowing agent, and a catalyst, and a small amount of an incyanate component containing a polyisocyanate compound. In a method of manufacturing a rigid foam by mixing two components and foaming and curing the polyol component, the polyol component contains a halogenated hydrocarbon foaming agent and a polyoxyethylene fatty acid ester surfactant in an amount greater than that soluble in the polyols. A method for manufacturing a rigid foam, characterized by: 2. Polyoxyethylene fatty acid ester surfactant has 50 or more oxyethylene groups
The method according to item 1 of the scope of Patent No. 8, characterized in that the castor oil-based surfactant is used in an amount of about 15 parts by weight or more per 100 parts by weight of the polyol. (v) The method according to claim 1, wherein the hard 7 ohm is a urethane-modified polyisocyanurate 7 ohm obtained by using an excess polyisocyanate compound and an incyanate trimerization catalyst with respect to the polyols. . 4. The method according to claim 3, wherein the polyol is a polyester polyol, a polyether polyol containing an oxyethylene group as an oxyalkylene group, or a polyol whose main component is a polyester ether polyol.